Potash

From Wikipedia, the free encyclopedia

Crystals of potash, with a U.S. penny for reference. (The coin is 19 mm (0.75 in) in diameter and copper in color.)

Potash (/ˈpɒtæʃ/) is some of various mined and manufactured salts that contain potassium in water-soluble form.[1] The name derives from pot ash, which refers to plant ashes soaked in water in a pot, the primary means of manufacturing the product before the industrial era. The word potassium is derived from potash.[2]

Potash is produced worldwide at amounts exceeding 90 million tonnes (40 million tonnes K2O equivalent) per year, mostly for use in manufacturing. Various types of fertilizer-potash thus constitute the single largest industrial use of the element potassium in the world. Potassium was first derived in 1807 by electrolysis of caustic potash (potassium hydroxide).[3]

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✪ American Potash Cake 18th Century Cooking with Jas Townsend and Son S5E17

✪ Organic Potash For Soap Making

✪ Free Range Chemistry 30 - Potassium from Potash

✪ फ़सल में पोटाश का काम/महत्त्व।Role of potash in crop.

✪ गेहू के फ़सल में पोटाश का महत्त्व।Potash Role in Wheat Crop.

Transcription

In just a little while, I’m going to be
making a recipe that’s very unusual and
very interesting. It’s not a recipe from
a cookbook, but it’s actually a recipe from
an editorial, or a letter to the editor, 1799.
This episode is a companion piece to go along
with our “Exploring the 18th Century”
series where we’re talking about leavening
or chemical leavening. Thanks for joining
us today on 18th Century Cooking with James
Townsend and Son.
If you haven’t watched Exploring the 18th
Century, I encourage you to do so. We are
discussing in depth our research into chemical
leavening in the 18th century and that will
help give you a much greater context for the
recipe that I’m making today.
Today’s recipe is for what was call American
potash cake. As I mentioned in the introduction,
it’s found in a letter to the editor in
the London Monthly Magazine. This letter was
written by Margaretta Curly, who at the time
was living in New York. In her letter, Mrs.
Curly expounds on the benefits of a cake that
uses no yeast. Rather, she uses potash or
pearl ash which is an alkaline that reacts
with an acid creating carbon dioxide bubbles
that lightens or leavens your cake as it bakes.
Mrs. Curly wrote about how these cakes could
be made in minutes rather than hours and they
were especially handy when yeast wasn’t
readily available. She also wrote about how
these cakes could be made using a variety
of ingredients.
Today we’re using her suggestion for making
them with rye and molasses, because sugar
and white flour were scarce in various regions
in North America. I’m cutting the original
recipe in half and I’m using a pound of
rye flour. It’s about 4 cups. You can use
wheat flour if you wish. To this, I’ll rub
in 4 ounces, or about, say, 8 tablespoons
of pork lard. If you don’t want to use pork
lard, you can use butter instead.
Once I have these combined well, I’ll turn
to my wet ingredients. I’ll start with a
cup of sour milk. Now if you don’t have
sour milk, you can take fresh milk and add
about a tablespoon of lemon juice or vinegar.
To this, I’ll add 4 ounces, that’s about
a half a cup, of light or Barbados molasses.
You really don’t want to use black strap
molasses. It’s too strongly flavored. You
can use 4 ounces or a half a cup of sugar
instead if you wish.
Now before I’ll add our dry and wet ingredients
together, I’ll take a ½ a teaspoon of pearl
ash and dissolve it completely in a quarter
of a cup of water. Add this to your milk mixture
and quickly add that to your flour.
We now offer pearl ash at James Townsend and
Son. You can substitute baking soda, but that
is a mid-19th century invention.
Mix this until blended and then turn out onto
a floured surface. Roll it out to about ½
or ¾ of an inch thick.
You can cut these any shape you wish. I’m
using a biscuit cutter.
You want to bake these at about 400 degrees
for 16-18 minutes.
Now notice the crumb on this. It’s very
light and fluffy. That’s definitely the
work of the pearl ash. Well, it’s got a
really nice flavor, a bit like, say, you know,
a breakfast biscuit, but with the molasses
and the rye flour, it’s definitely got a
nuttier flavor, and one of the interesting
things I thought about this recipe was that
there was no salt, so you can tell it’s
a little lacking in salt, but really not bad
at all. I think the potassium in the pearl
ash really helps give it a little of salty
flavor anyway.
Now I went ahead and also made a recipe using
regular wheat flour instead of rye flour and
using butter instead of lard. Now that rye
and lard flour version is very, very inexpensive.
This is a more expensive version, but let’s
see how this turned out. It’s got sugar
instead of molasses too, so it’s missing
that molasses flavor, much more like what
you would expect as a modern sort of breakfast
biscuit. It’s a little bit sweeter. You
know, it actually almost reminds me of a shortbread
that you would use for strawberry shortbread.
It’s kind of that sweet and that kind of
yummy.
This recipe of Mrs. Curly’s in 1799 in this
London Monthly Magazine gives us a great little
snapshot of something that’s going on right
there in the Hudson River valley, where we
see this knowledge being spread from the Dutch
community, probably right there in the mid-18th
century, and it spreads, where she’s giving
that knowledge about how you can leaven breads,
not with just yeast, but with this new method.
Anyway, a couple of years later, the recipe
was published in the Domestic Encyclopedia
of London. In 1808, Duncan McDonald picked
up the recipe and included it in his cookbook,
The New London Family Cook and while chemical
leavening was much more quickly accepted in
North America than in Great Britain, it does
begin to slowly emerge in the 1820’s and
30’s in English cookbooks.
Again, if you haven’t watched our “Exploring
the 18th Century” series where we’re discussing
chemical leavening, I really encourage you
to do so. We really get to go in depth and
tease out these ideas of where chemical leavening
comes from.
If you’re new to our YouTube channel, I
really want to welcome you, and don’t forget
to subscribe by pressing this button right
up here. If you‘d like to visit our website,
this link will take you here, and if you’d
like to request a print catalog, this link
will take you to that spot. We also have related
video links right down here. Just click on
them, it’ll take you right to the video.
Thank you so much for watching.

Contents

Terminology

Potash refers to potassium compounds and potassium-bearing materials, the most common being potassium chloride (KCl). The term potash comes from the Middle Dutch word potaschen (pot ashes, 1477).
[4]
The old method of making potassium carbonate (K2CO3) was by collecting or producing wood ash (an occupation carried out by ash burners), leaching the ashes and then evaporating the resulting solution in large iron pots, leaving a white residue called pot ash.[5] Approximately 10% by weight of common wood ash can be recovered as pot ash.[6][7] Later, potash became the term widely applied to naturally occurring potassium salts and the commercial product derived from them.[8]

The following table lists a number of potassium compounds which use the word potash in their traditional names:

Production

All commercial potash deposits come originally from evaporite deposits and are often buried deep below the earth's surface. Potash ores are typically rich in potassium chloride (KCl), sodium chloride (NaCl) and other salts and clays, and are typically obtained by conventional shaft mining with the extracted ore ground into a powder.[12] Other methods include dissolution mining and evaporation methods from brines.

In the evaporation method, hot water is injected into the potash which is dissolved and then pumped to the surface where it is concentrated by solar induced evaporation. Amine reagents are then added to either the mined or evaporated solutions. The amine coats the KCl but not NaCl. Air bubbles cling to the amine + KCl and float it to the surface while the NaCl and clay sink to the bottom. The surface is skimmed for the amine + KCl which is then dried and packaged for use as a K rich fertilizer—KCl dissolves readily in water and is available quickly for plant nutrition.[13]

Potash deposits can be found all over the world. At present, deposits are being mined in Canada, Russia, China, Belarus, Israel, Germany, Chile, the United States, Jordan, Spain, the United Kingdom, Uzbekistan and Brazil,[14] with the most significant deposits present in Saskatchewan, Canada.[citation needed]

History of production

The first U.S. patent was issued for an improvement "in the making of Pot ash and Pearl ash by a new Apparatus and Process"; it was signed by then President George Washington.

A covered hopper car in a Canadian train for shipping potash by rail.

Potash (especially potassium carbonate) has been used in bleaching textiles, making glass, and making soap, since about AD 500. Potash was principally obtained by leaching the ashes of land and sea plants. Beginning in the 14th century potash was mined in Ethiopia. One of the world's largest deposits, 140 to 150 million tons, is located in the Tigray's Dallol area.[15] Potash was one of the most important industrial chemicals. It was refined from the ashes of broadleaved trees and produced primarily in the forested areas of Europe, Russia, and North America. The first U.S. patent of any kind was issued in 1790 to Samuel Hopkins for an improvement "in the making of Pot ash and Pearl ash by a new Apparatus and Process".[16]Pearl ash was a purer quality made by calcination of potash in a reverberatory furnace or kiln. Potash pits were once used in England to produce potash that was used in making soap for the preparation of wool for yarn production.

As early as 1767, potash from wood ashes was exported from Canada, and exports of potash and pearl ash (potash and lime) reached 43,958 barrels in 1865. There were 519 asheries in operation in 1871. The industry declined in the late 19th century when large-scale production of potash from mineral salts was established in Germany. In 1943, potash was discovered in Saskatchewan, Canada, in the process of drilling for oil. Active exploration began in 1951. In 1958, the Potash Company of America became the first potash producer in Canada with the commissioning of an underground potash mine at Patience Lake; however, due to water seepage in its shaft, production stopped late in 1959 but following extensive grouting and repairs, resumed in 1965. The underground mine was flooded in 1987 and was reactivated for commercial production as a solution mine in 1989.[7]

In the late 18th and early 19th centuries, potash production provided settlers in North America a way to obtain badly needed cash and credit as they cleared wooded land for crops. To make full use of their land, settlers needed to dispose of excess wood. The easiest way to accomplish this was to burn any wood not needed for fuel or construction. Ashes from hardwood trees could then be used to make lye, which could either be used to make soap or boiled down to produce valuable potash. Hardwood could generate ashes at the rate of 60 to 100 bushels per acre (500 to 900 m3/km2). In 1790, ashes could be sold for $3.25 to $6.25 per acre ($800 to $1,500/km2) in rural New York State – nearly the same rate as hiring a laborer to clear the same area. Potash making became a major industry in British North America. Great Britain was always the most important market. The American potash industry followed the woodsman's ax across the country. After about 1820, New York replaced New England as the most important source; by 1840 the center was in Ohio. Potash production was always a by-product industry, following from the need to clear land for agriculture.[17]

Most of the world reserves of potassium (K) were deposited as sea water in ancient inland oceans. After the water evaporated, the potassium salts crystallized into beds of potash ore. These are the locations where potash is being mined today. The deposits are a naturally occurring mixture of potassium chloride (KCl) and sodium chloride (NaCl), more commonly known as table salt. Over time, as the surface of the earth changed, these deposits were covered by thousands of feet of earth.[17]

Most potash mines today are deep shaft mines as much as 4,400 feet (1,400 m) underground. Others are mined as strip mines, having been laid down in horizontal layers as sedimentary rock. In above-ground processing plants, the KCl is separated from the mixture to produce a high-analysis potassium fertilizer. Other potassium salts can be separated by various procedures, resulting in potassium sulfate and potassium-magnesium sulfate.

Today some of the world's largest known potash deposits are spread all over the world from Saskatchewan, Canada, to Brazil, Belarus, Germany, and the Permian Basin. The Permian basin deposit includes the major mines outside of Carlsbad, New Mexico, to the world's purest potash deposit in Lea County, New Mexico (not far from the Carlsbad deposits), which is believed to be roughly 80% pure. (Osceola County, Michigan has deposits 90+% pure, however, the only mine there was recently converted to salt production.) Canada is the largest producer, followed by Russia and Belarus. The most significant reserve of Canada's potash is located in the province of Saskatchewan and is currently mined by The Mosaic Company, Nutrien and K+S.[1]

In the beginning of the 20th century, potash deposits were found in the Dallol Depression in Musely and Crescent localities near the Ethiopean-Eritrean border. The estimated reserves are 173 and 12 million tonnes for the Musely and Crescent, respectively. The latter is particularly suitable for surface mining; it was explored in the 1960s but the works stopped due to the flood in 1967. Attempts to continue mining in the 1990s were halted by the Eritrean–Ethiopian War and have not resumed as of 2009.[18]

Recently, recovery of potassium fertilizer salts from sea water has been studied in India.[19] During extraction of salt from seawater by evaporation, potassium salts get concentrated in bittern, an effluent from the salt industry.

In 2013, almost 70% of potash production was controlled by Canpotex, an exporting and marketing firm, and the Belarusian Potash Company. The latter was a joint venture between Belaruskali and Uralkali, but on July 30, 2013 Uralkali announced that it had ended the venture.[20]

Consumption

Production and reserves of potash (both in K2O equivalent)(2017, in million tonnes)[21]

Fertilizers

Potassium is the third major plant and crop nutrient after nitrogen and phosphorus. It has been used since antiquity as a soilfertilizer (about 90% of current use).[6] Elemental potassium does not occur in nature because it reacts violently with water.[22] As part of various compounds, potassium makes up about 2.6% of the Earth's crust by mass and is the seventh most abundant element, similar in abundance to sodium at approximately 1.8% of the crust.[23] Potash is important for agriculture because it improves water retention, yield, nutrient value, taste, color, texture and disease resistance of food crops. It has wide application to fruit and vegetables, rice, wheat and other grains, sugar, corn, soybeans, palm oil and cotton, all of which benefit from the nutrient’s quality-enhancing properties.[24]

Demand for food and animal feed has been on the rise since 2000. The United States Department of Agriculture's Economic Research Service (ERS) attributes the trend to average annual population increases of 75 million people around the world. Geographically, economic growth in Asia and Latin America greatly contributed to the increased use of potash-based fertilizer. Rising incomes in developing countries also was a factor in the growing potash and fertilizer use. With more money in the household budget, consumers added more meat and dairy products to their diets. This shift in eating patterns required more acres to be planted, more fertilizer to be applied and more animals to be fed—all requiring more potash.

After years of trending upward, fertilizer use slowed in 2008. The worldwide economic downturn is the primary reason for the declining fertilizer use, dropping prices, and mounting inventories.[25][26]

The world's largest consumers of potash are China, the United States, Brazil, and India.[27] Brazil imports 90% of the potash it needs.[27] Potash consumption for fertilizers is expected to increase to about 37.8 million tonnes by 2022.[28]

Potash imports and exports are often reported in K2O equivalent, although fertilizer never contains potassium oxide, per se, because potassium oxide is caustic and hygroscopic.

Pricing

At the beginning of 2008, potash prices started a meteoric climb from less than US$200 a tonne to a high of US$875 in February 2009.[29] These subsequently dropped dramatically to an April 2010 low of US$310 level, before recovering in 2011–12, and relapsing again in 2013. For reference, prices in November 2011 were about US$470 per tonne, but as of May 2013 were stable at US$393.[30] After the surprise breakup of the world's largest potash cartel at the end of July 2013, potash prices were poised to drop some 20 percent.[31] At the end of Dec 2015, potash traded for US$295 a tonne. In April 2016 its price was US$269.[32] In May 2017, prices had stabilised at around US$216 a tonne down 18% from the previous year. By January 2018, prices have been recovering to around US$225 a tonne.[33] However, it is noteworthy that world potash demand tends to be price inelastic in the short-run and even in the long run.[34]

Substitutes

No substitutes exist for potassium as an essential plant nutrient and as an essential nutritional requirement for animals and humans. Manure and glauconite (greensand) are low-potassium-content sources that can be profitably transported only short distances to crop fields.[21]